Vat dyestuffs



Patented Jan. 17, 1939 VAT DYESTUFFS Willy Eichholz, Mannheim, Germany, assignor to General Aniline Works, Inc., New York, N. Yq, a corporation of Delaware Noe Drawing. Application January 30,. 1937, Se-..

rial No. 123,147. In Germany." February 6,

1a ma The present invention relates to a process of producing vat dyestufis;

In the U. S. Patent 2,025,546 there are described t yestuf s and-a proeessr p heir production accord ng o. h eb .2..-di,an b q inon phide,. he mmands .oiv he. nature of. nt ;r i inonylrsulphoxide bta nable. th r f m o datio deriv iiv sef he. d. b t c are treated while heating with zinc chloride.

to hai wiq nd. thatthesaid dyestufis be. obtained. a. spec ally advantageousmanner y. n na luminium n. hepres nce of 1- phuric acid to act on the said initial. materials instead of zinc chloride. The yield of dyestuffs m can be increased by carrying; out the reaction in the presence of -catalysts, such, as nitrosyl-sulphuric acid or the oxides; of acid-forming elements oi. the 5th .to the 7th groups of the periodic system or the acids appertaining thereto. For

example the oxides and acids; of vanadium, chromium, tungsten and; manganese are suitable.

The dyestuffs maybepurified for example by precipitation in stagesfirom sulphuric acid. The said purification may also be combined. with the preparation of thedyestuffs.

The new method of working is distinguished by the fact that it is easier to carry out than that already:.=known, inparticularbecause considerably lower temperatures. maybe i used: as e forexample between and 70 C even without the supply of heat.

The following examples will further illustrate ow e a d twent es: h arr ed ut n. p a c b t n n i n t r s ar a o these e ampl s. h pa s-ere hr w i ht Example-1 means of ZOO-partsof; 62 per cent sulphuric acid.

Fine green needles are thus obtained which correspond to the dyestufi obtained according to Example 1 in the said U. S. patent.

If the 1-(4-methylanthraquinonyl)-2' anthrathen precipitated in stages at about 4.0;. G

il ne e u m ehaviee a e tinereint im e 7 to 7 aina e by he eee qa i-r chlor lrmethylanthraquinone with 1 anthr u i-.: nQn e-Z -mercaptan sodium salt in twig ter, be. used;

as initial material, a dyestuff;-whicl probablxhas 5 the following composition; V

to the dyestufi specified in thezfirst paragraph of this example.

Emamplaz 0.5 part of pyrolusite isadded to a solution of 25k 10 parts of 1.2-dianthraquinonyl-sulphide in 200 parts of fuming sulphuric acid containing 1 per cent of sulphurtrioxide. 2, parts of aluminium powder are then added during the course of about three hours at about 40C. The mixture is stirred 3 at about 40 C. until. it has become red-brown, water or dilute sulphuric.acid then being slowly added until the sulphuric aqid content amounts to about 83 percent. The dyestufl which has separatedaintthelform of green needles, is filtered off by suction, washed with 83 percent sulphuric .acid andwateriand dried.

Ex pl 3:

scribed in Example 2.

If the 1.2-dianthraquinonyl-sulphide be replaced by l-anthraquinonyl-2-(3-methylan- 50 thraquinonyl) -sulphide' (obtainable from Z-methylanthraquinone-B-mercaptan sodium salt by reaction with l-chloranthraquinone in aqueous suspension) a similar dyestufi is obtained which probably has the following composition Example 4 2 parts of aluminium powder are introduced at from 35 to 40 C. during the course of about five hours into a solution of 10 parts of 1.2-dianthraquinonyl-sulphide in 100 parts of sulphuric acid monohydrate. After themixture has assumed a red-brown color, it is introduced into 1000 parts of water. The resulting dark'green precipitate is filtered off by suction, washed and dried. In order to removereadily soluble impurities, the 'dyestufi is first treated at ordinary temperature with nitrobenzene and; after removing adherent nitrobenzene, the remaining dyestufi is precipitated in stages from sulphuricacid. Compact .dark green needles are thus obtained which are converted into paste form in the usual way.

If the 1.2-dianthraquinonyl-sulphide be replaced by the 1-(2-methylanthraquin0ny1) -2'- anthraquinonyl-sulphide chlor-Lmethylanthraquinone by reaction. with anthraquinone-Z-mercaptan sodium salt, adye- 'stuif is obtained which is very similar to that described above in a chemical and tinctorial respect and which probably has the following composi-- tion CHI '7 Emample 5 0.4 part oi aluminium powder is introduced during the course of three hours at from 35 to 40 G. into a solution of 2 parts of 2-chlor-3.1'-

dianthraquinonyl-sulphide (prepared by the reaction of 2- chloranthraquinone-B-mercaptan sodium salt with l-chloranthraquinone in an aqueous medium) in 20 parts of sulphuric acid monohydrate, the mixture being stirred for about 15 hours at the said temperature. It thus as sumes a dark orange-red coloration. It is poured into water, boiled and the dyestuif which has been precipitated in the form of bluish green obtainable from 1-.

I 30 to -70 C.,

flakes is filtered off by suction. It is freed from readily soluble impurities by washing with acetone, dried and precipitated from sulphuric acid. It yields somewhat more bluish dyeings than the dyestufi free from chlorine.

What I claim is: V

'1. A process of producing vat dyestuffswhich comprises heating at a temperature of between 30 and 70 C. -a compound corresponding to the general formula in which X stands for a member selected from the class consisting of --S--.and

and Y stands for a substituent selected from the class consisting of I halogen and low molecular. alkyl; in the presence of sulphuric acid and .alu-' minium, the aluminium being continuously added. in an amount sufiicient to obtain a green vat dyestuff.

2.,A process of producing vat dyestuffs which comprises heating at a temperature of between 30;to 70 C. a compound corresponding. to the general formula in which X standsrfor a member selected from the class consisting of S-- and and Y stands for a substituent selected from the class consisting of halogen and low molecular alkyl, in the presence of sulphuric acid and aluminium, the metal being continuously added in amounts suflicient to obtain a green vat dyestufi. V 7

3. A process of producing vat dyestuffs which comprises heating at a temperature .of between acting as catalyst, 1.2-dianthraquinonyl sulphide in the presence of sulphuric acid and adding aluminium in amounts sufficient to obtain a green vat dyestuff. I

' V WILLY 'EICl-IHOLZ.

in. the presence of vanadic acid 

